The term ‘coin’ is used to mean any discoid body such as, but not limited to, monetary coins, tokens, medals and other such similar items.
Conventional approaches to coin validation are varied and numerous. For example, EP-A-2,242,029 describes a coin singulating and testing device comprising a collection box casing enclosing an inclined motorised rotor. The rotor includes a plurality of coin receptacles for receiving and transporting coins in a circular manner passed a sensor device for determining if the coins are genuine.
The device disclosed in EP-A-2,242,029 includes a flap in the floor of the circular coin path that can be selectively opened and closed. When a coin is determined to be genuine, the flap is held open such that the coin falls under gravity into a delivery opening.
With other conventional coin validation devices a coin typically traverses a pathway through a sensor region by rolling edgewise down an inclined sensing track. A problem arises with this approach in that the coin is unstable and will wobble leading to undesirable coin-to-coin variations in the electromagnetic coupling between the sensing coils and the coin under test. Coin wobble can be reduced by narrowing the sensor region passageway, but this increases the likelihood of coins becoming jammed, especially if the throughput of coins is erratic or irregular.
For reliable coin validation various properties of a coin need to be detected. Typically, this is achieved using discrete frequency analysis, but this leads to an increase in the number of sensor coils required, and the speed of operation imposes a limit on the rate at which coins can be validated.
The present invention seeks to address the problems associated with prior art devices.